In a research project focusing on extreme cases or deviant sampling, why might a researcher choose to study an outlier case rather than a typical case?

In a research project focusing on extreme cases or deviant sampling, a researcher might choose to study an outlier case rather than a typical case for several reasons:

1. Unique Insights: Outlier cases can provide unique insights that are not available in typical cases. They can reveal processes and phenomena that remain hidden in more 'normal' cases.

2. Challenging Existing Theories: Studying outliers can challenge existing theories and assumptions. If a theory cannot account for the outlier, it may need to be revised or replaced.

3. Enhancing Understanding: Outliers can enhance our understanding of the subject matter. They can show us the full range of possibilities, not just the average or typical cases.

4. Generating New Theories: Outliers can also be the source of new theories. By studying the unusual, researchers can come up with new ideas and hypotheses.

5. Testing the Robustness of a Theory: Outliers can be used to test the robustness of a theory. If a theory can explain both the typical and the outlier cases, it is a strong theory.

In conclusion, while studying typical cases can provide a general understanding, focusing on outlier cases can offer deeper and more comprehensive insights.